Study on the temperature field in the cutting zone for machining monocrystalline silicon wafer using free abrasive multi-wire saw

With increasing applications of integrated circuits, the requirements for the quality of the corresponding substrate silicon wafers have become more stringent. Slicing is a key step in the manufacturing of silicon wafers. At present, free-abrasive multi-wire saw (MWS) technology is commonly employed for substrate silicon wafer processing. However, the actual temperature field in the cutting zone is unclear because of the narrow cutting zone in multi-wire sawing. Although a simulation method was adopted in this study, the distribution of the slurry in the cutting zone remains ambiguous, causing a large difference between the simulation results. The temperature field is an important cause of warpage, which significantly affects wafer quality. In this study, an experiment and simulation of the temperature field in the cutting zone of a MWS of monocrystalline silicon with free abrasives were performed. First, an experiment was designed to measure the temperatures at different positions in the cutting zone. Then, based on the experimental data of the fluid pressure distribution and the temperature field in the cutting zone, after obtaining the heat source model, a simulation analysis was conducted, and the results are consistent with the experimental results. Finally, based on the heat flux model, the temperature field distribution in the cutting zone under different cutting conditions was simulated and analyzed. Temperatures of 36.7, 39.4, 40.7, and 42.8 °C were obtained at 22.5, 62.5, 137.5, and 177.5 mm, respectively, from the slurry entrance in the cutting zone. According to the heat source model based on the pressure distribution data of slurry in the cutting zone, the temperature values obtained via simulation at 22.5, 62.5, 137.5, and 177.5 mm from the slurry inlet were 35.4, 37.4, 41.5, and 43.1 °C, respectively. The maximum temperature difference is 1.8K°C, and the average temperature difference is 0.2K°C. Thus, the validity of the heat source model was verified. Further, based on the heat source model, the maximum temperature for cutting a 300-mm monocrystalline silicon wafer was predicted as 48.4 °C. Moreover, the wire speed was found to greatly influence the maximum temperature in the cutting zone. Tension also affects the temperature of the cutting zone, but to a lesser extent than the wire speed.